2004 Madrid train bombings

The 2004 Madrid train bombings were ten coordinated explosions at the Atocha Station, El Pozo station, Santa Eugenia station, and Calle Tellez in Madrid, Spain. The attacks killed 191 people and wounded 2,050, and al-Qaeda claimed responsibility for the bombings (although Spanish authorities initially believed that the Basque ETA were responsible).

Background
In 2003, Spanish Prime Minister Jose Maria Aznar allied with the United States and United Kingdom in the Iraq War, deploying Spanish troops to occupy Iraq. The war was very controversial, and it gave al-Qaeda more strength as they appealed to Muslims to fight the "crusaders" (most of the coalition countries were predominantly-Christian) that invaded Afghanistan and Iraq. As a consequence of Spain's involvement in the Iraq War, a group of Muslims in Spain linked to either the Moroccan Islamic Combatant Group (GICM) or local cells of al-Qaeda worked together to put together a series of bombings in the Spanish capital of Madrid on the metro.

Bombings
At 7:37 AM, a first bomb exploded and two other bombs exploded within four seconds of each other at 7:38 on Train 21431 at the Atocha Station. Also at 7:38, two bombs exploded in different carriages of Train 21435 at El Pozo del Tio Raimundo Station, while one bomb blew up at the Santa Eugenia Station. The last four bombs went off 800 meters from the Atocha Station on Train 17305 on the Calle Tellez at 7:39. The attack left 142 Spanish, 16 Romanians, 6 Ecuadorians, 4 Poles, 4 Bulgarians, 3 Peruvians, 2 Dominicans, 2 Colombians, 2 Moroccans, 2 Ukrainians, 2 Hondurans, 1 Senegalese, 1 Cuban, 1 Chilean, 1 Brazilian, 1 French, and 1 Filipino dead (191 total). It was the deadliest terrorist attack since the Lockerbie bombing of 1988, which killed 270 people.

Aftermath
Spain arrested Jamal Zougam, Otman el-Ghanoui, Jose Emilio Suarez Trashorras, Abdelmajid Bouchar, Basel Ghalyoun, Rabei Osman Sayed Ahmed, Youssef Belhadj, and Hasan el Haski, with 20 others being charged and 5 of them being found not guilty; two of them were later released after the charges were dropped in 2008. The bombings were successful in their purpose of forcing Spain to leave Iraq, as the supporters of the People's Party that were intimidated by the attack now voted for the Spanish Socialist Workers' Party, and the newly-elected Prime Minister Jose Luis Rodriguez Zapatero (who took office three days later) promised to withdraw Spanish troops from Iraq.